You always want to do the best job that you can when taking care of fish. Plecos are supposed to be fairly hardy fish, and this likely made you confident enough to purchase some even as a beginner.
Problems can occur when caring for plecos. If your pleco fish doesn’t appear to be moving, you’re likely going to be incredibly concerned.
Why would a pleco fish stop moving entirely? Is the fish dead or is it really sick?
Continue reading to learn about reasons why plecos might stop moving. It might help you to figure out how to help the fish by doing some troubleshooting.
Is the Pleco Dead?
The first thing you should consider is whether the pleco has died or not. It very well might be dead if it doesn’t appear to be moving at all.
When a pleco fish dies in the fish tank, it’ll stop moving and it’ll float. There are other reasons why a pleco might start floating, but it’s possible that the fish could be dead.
Look at the fish closely and try to see if its gills are moving. Do you see the gills moving at all or are they truly motionless?
If you can’t see the gills moving, this suggests that the fish is truly dead. You shouldn’t count the fish out completely just yet, though.
Try touching the fish and see if it reacts. If the fish is still alive, it should move when you touch it.
You don’t have to reach into the tank and touch it with your bare hand. Use a fish net or scoop to touch the fish gently to test whether it’s alive or not.
If you get no response, the fish is surely dead. You’ll want to scoop the fish out of the tank and dispose of it.
Pleco Not Moving but Breathing
If the pleco is not moving but breathing, then there are several things that could be happening. The fish might be very sick and it feels unable to move.
Many different types of illnesses will make fish feel lethargic. Some will also cause fish to have a hard time breathing.
Does the fish appear to be gasping for air? It could be that the fish is sick and has some type of problem with its gills.
Another potential problem involves the oxygen levels in the tank being too low. Plecos need to be kept in fish tanks with high oxygen levels.
If the oxygen levels get really low, plecos might stop moving. Sometimes plecos will just float near the top of the tank when the oxygen levels aren’t sufficient.
You’ll want to fix issues with the oxygen levels being too low. Test to see if your ammonia, nitrate, and nitrite levels are too high.
You should be testing the water parameters regularly to protect the fish. It’s also important to clean the fish tank and do regular water changes to avoid throwing the water parameters off.
Plecos Are Nocturnal
It’s also possible that nothing is wrong at all. You see, plecos are nocturnal fish that like to hide and rest during the day.
If the fish is hiding among the plants or in a cave and not moving, that’s perfectly normal. These fish simply aren’t active during the day.
They do things at night and you’re not going to see them scurrying about much when the sun is out. If you want fish that are livelier during the day, you’d be better off looking for a different type of fish.
As long as nothing appears to be wrong with the fish, it’s not necessary to worry. If the fish is breathing, it’s likely that it’s simply resting.
When you try to touch the fish, it’s going to react and swim away. This is perfectly normal behavior for plecos.
The Fish is Still New
When plecos are just getting used to a new environment, they’re going to be rather skittish. It’s normal for these fish to hide and be very wary of venturing out.
A pleco might choose to remain very still and stay in the same spot all day. This is normal behavior when the fish is just introduced to a fish tank.
Have you bought the pleco in question within the last week or so? It might need a bit more time to get used to its new environment.
You can make acclimating to the tank easier for the fish by taking the time to float the bag before putting it in the tank. This process involves floating the bag on top of the tank.
You transfer water from the aquarium to the bag while slowly removing water from the bag. Floating the fish for an hour or so will help it to get used to the water temperature of its new home.
Fish that are acclimated in this fashion become comfortable in new tanks faster. It still might take plecos a bit to feel bold enough to swim around.
You also have to keep in mind that they’re nocturnal. They aren’t necessarily fish that will swim around and show off for you during the day under normal circumstances.
It might be normal to see a pleco breathing but not moving. These fish enjoy hiding and they often stay in the same place at the bottom of the aquarium.
Also, they’re nocturnal fish that rest during the day. The fish could be just fine since it’s resting during the day.
If the fish appears to be sick, then it might not be moving because it has some type of disease. Disease can make fish sluggish and it can also cause them to stop eating.
Stress will make fish stop moving and acting normally, too. Many things can cause stress such as poor water conditions, overcrowded fish tanks, and incompatible tank mates.
If the fish isn’t moving or breathing, it’s possible that it’s dead. You’ll want to try to touch the fish to see if it reacts at all.
A fish that doesn’t react to being touched is probably dead. Hopefully, that won’t be the case for your fish.
Jeff has always enjoyed having pets, but as a child, he was drawn to his family’s fish tank. Being able to maintain a small ecosystem and observe the behaviors and interactions in the underwater world peaked his interest early on and has kept him hooked until this day. On Avid Aquarist, Jeff shares everything he’s learned about helping aquatic life survive and thrive in a home aquarium.